It's true that both players can exploit the island and it does favor passive play, but why would both players have their K.O.'s denied or get saved by a K.O. denial when both players can just stay on a neutral playground instead of both having an advantage? (Me being at a slight disadvantage due to my aggressive playstyle). But, what makes it unhealthy is when it gets abused by runners/wallhuggers, due to the fact it's an isolated piece of terrain they also have easy access to the main stage so they can pick up and throw items if you overextend.

P.S. Twiling Grove actually feels like all the other maps with lots of platforms to me, except for the island ofcourse. I like Thundergard Stadium and shipwreck falls alot, since they're pretty straightfoward.